The invention relates to a method for regulating or controlling the temperature of an interior space, especially that of a motor vehicle, by setting the temperature of a medium. The medium flows out of an actuating device and acts thermally on the interior space. The temperature of the medium is set using a control and regulating device as a function thereof, via signals which can be supplied to an interior temperature sensor input connection, an outlet-flow temperature sensor input connection and one user setting variable input connection. The invention further relates to a device which is suitable for carrying out the method.
Methods of the above-described type are known, for example, for heating or air-conditioning systems in motor vehicles. Air, which is supplied from the exterior to a heat exchanger, which forms a part of the actuating device, and is blown out from there into the vehicle interior, forms the medium which acts thermally on the interior space, and at the same time also forms the interior medium itself.
German Patent document DE 41 23 882 A1 discloses a heating system for the interior of a motor vehicle. The heating system operates in an interior temperature regulation mode, in such a manner that a required interior temperature which is desired by the user can be preset as the control variable of an outer control loop whose setting variable is the blowing-out temperature of the air. The setting variable acts as a control variable on an inner control loop which regulates the blow-out air temperature in a corresponding manner.
Such known interior temperature regulation frequently can no longer be sensibly carried out in a vehicle if bodywork openings in the vehicle are open and the vehicle interior is, as a consequence, subjected to an exchange of air with the exterior atmosphere over a large area. This applies in particular to vehicles having a roof which can be optionally opened or closed, for example, in the case of a convertible. For this reason, a vehicle air-conditioning system, such as is disclosed in European Patent document EP 0 375 871 B1 (U.S. Pat. No. 5,003,785), provides a switching device which detects the state of the vehicle's bodywork interior opening. If an opening of the bodywork opening is detected, the switching device switches over from internal temperature control, in the case of which the required setting of a temperature mixing valve is set as a function of the actual interior temperature, the required interior temperature and the actual blown-out air temperature, to a blowing-out temperature control. In the blowing-out temperature control, the required setting of the temperature mixing valve is now set only as a function of the required interior temperature and of the actual blow-out air temperature.
The present invention is based on the technical problem of providing a method and a device of the above-mentioned type for regulating or controlling the temperature of an interior such that, using the method and device, an interior temperature setting is possible in a manner that matches as well as is possible with the respective situation, both when an interior temperature sensor and an outlet flow temperature sensor are present and in the absence of one of the two sensors, or both sensors, and which are particularly suitable for vehicles whose roof can be optionally opened and closed.
The present invention overcomes this problem by providing a method for regulating or controlling the temperature of an interior space, especially for a motor vehicle, by setting the temperature of a medium, which flows out of an actuating device and acts thermally on the interior, via a control and regulating device as a function thereof, using signals which can be supplied to an interior temperature sensor input connection, an outlet-flow temperature sensor input connection and at least one user setting variable input connection. The signals to the temperature sensor input connections are evaluated by the control and regulating device in order to identify whether the associated temperature sensors have been connected such that they can operate. Optionally, depending on this, an interior temperature-regulation mode in which the variable set by the user is treated as the required interior temperature value and the outlet-flow temperature is regulated by means of a required out flow temperature value, which is dependent on the interior temperature regulation difference, if both an interior temperature sensor, connected such that it can operate, and an outlet-flow temperature sensor, connected such that it can operate, have been identified. Alternatively, an outlet-flow temperature regulation mode in which the variable set by the user is treated as the required outlet-flow temperature value and the outlet-flow temperature is regulated as a function of this required value, if an interior temperature sensor, connected such that it cannot operate, and an outlet-flow temperature sensor, connected such that it can operate, have been identified. Or, a reversionary control mode is activated, in which the variable set by the user is treated directly as the setting variable for the actuating device, and the actuating device is set in a corresponding manner, if both an interior temperature sensor, connected such that it cannot operate, and an outlet-flow temperature sensor, connected such that it cannot operate, have been identified.
A device operating in accordance with the method includes a control and regulating device, at least one user-controllable setting device, whose output connection is connected to a user setting variable input connection of the control and regulating device, an interior temperature sensor and an outlet flow temperature sensor, whose outputs are connected to respective input connections of the control and regulating device, and an actuating device, which is controlled by the control and regulating device for the outlet flow of the medium, which is at the outlet-flow temperature, into the interior space. The control and regulating device, for each input connection for a temperature sensor, confirms whether the temperature sensor is connected to the relevant input connection such that it can operate. The control and regulating device implements the interior temperature regulation mode, the outlet-flow temperature regulation mode and the reversionary control mode. The control and regulating device also includes a switching device, to which the output signals of the sensor connection confirmation system are supplied and which, as a function of this, activate the internal temperature regulation mode, the outlet-flow temperature regulation mode or the reversionary control mode.
The control and regulating device is constructed such that it identifies which temperature sensors are connected such that they can operate, and selects the suitable operating mode for interior temperature setting accordingly. This makes possible a sensible interior temperature setting mode by controlling or regulating using the same control and regulating device in each case if one of the two, or even both, temperature sensors is or are in a condition such that it or they cannot operate. The particular means required for this purpose, via which the control and regulating device operates, are individually familiar to one of ordinary skill in the art and can be implemented in hardware terms as corresponding electrical modules or even, at least partially, in software terms in conjunction with a microprocessor.
In one embodiment of the present invention, it is sufficient to provide a single user-operable setting device for all three intended operating modes. The control and regulating device interprets the value set by the user in a respectively appropriate manner for the present operating mode. A further embodiment provides a preferred simple and user-friendly arrangement.
In a further embodiment of the present invention, the temperature sensors are configured as temperature-dependent resistors which are in each case supplemented in the control and regulating device to form a voltage divider as means for confirming the connection of a sensor which is capable of operation. This is because the voltage divider provides a voltage signal which is characteristic of the respective state and can be evaluated in a corresponding manner by the control and regulating device in each case for a connection which is not connected, a connection which is short-circuited, and a correct sensor connection.
In the case of an advantageous further embodiment of the invention, a device which is suitable for installation in a motor vehicle and has a bodywork opening which can open, for example having a roof which can open, has a bodywork opening position identification switch whose state is detected by the control and regulating device. The device activates the blowing-out temperature regulation mode on identification of an at least partially open bodywork open position, and in this manner prevents an interior temperature regulation mode being carried out, which would no longer be expedient in this case.
The identification switch is preferably looped into the connection circuit for the interior temperature sensor so that, if a bodywork opening is open, this connection circuit is interrupted and an interior temperature sensor, which is connected such that it cannot operate, is thus simulated. As a result of which, the control and regulating device activates the outlet-flow temperature regulation mode, without requiring an additional signal input for the identification switch.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.